But as well as the effects on the liver and the lungs, both also hugely increase the risk of mouth cancer.

More than 5,000 people each year are diagnosed with the illness and almost 2,000 a year die from it – the equivalent of one every five hours.

In the last decade, there has been a 41 per cent increase in cases.

Tobacco and alcohol increase the risk, as does contracting Human Papilloma Virus, which is transmitted through close contact like kissing and is also linked to cervical cancer.

Throughout November, Mouth Cancer Action Month, oral health specialists in Leeds are highlighting the importance of keeping teeth and gums healthy and going for regular check-ups.

Being diagnosed with mouth cancer early improves the chances of survival from 50 to 90 per cent.

Early warning signs include ulcers which do not heal within three weeks, red and white patches or unusual changes in the mouth.

Kathy Fox, oral health improvement team co-ordinator at NHS Leeds' special care dentistry service, said: "We want to encourage a life-long habit of good oral healthcare by making small steps now, particularly with young people.

"And when we look after our teeth and gums we also improve our general health and can minimise our risk of mouth cancer.

"Three-quarters of cases are linked to tobacco and alcohol, so it is important that we raise awareness, urge smokers to quit, and encourage the drinking of alcohol in moderation."

She said simple measures could really improve oral health:

Going to a dentist regularly

Brushing gums and teeth for two minutes twice a day

Keeping sugary foods and drinks to mealtimes only

Checking mouth for ulcers, sore patches or changes

Dr Calvin Booth, clinical director of the special care dentistry service, said: "Education and awareness shows how easy it is for good, simple oral health habits and lifestyle choices to make a big difference.

"Prevention is the key to improving both oral and general health and also reducing the risk of more serious problems.

"Visit a dentist regularly and check your mouth as often as possible, it could just save your life."

Sessions have also been organised across the city to teach children and young people about the importance of good oral health.

The next one is at the Friday Night Project on Friday at the Laser Centre in Armley.

For more information on mouth cancer, log on to www.mouthcancer.org.